Rotary hammer drill



Feb. 16, 1932. e. A. BILLSTROM ROTARY HAMMER DRILL Filed Aug. 20. 1930gwua'ntov a (2m Infill Mme Patented Feb. 16, 1932 PATENT OFFICE UNITEDSTATES GUSTAVIS ADOLPHIS BILLSTBOI, 01: READ, COLORADO ROTARY HAMMERDRILL Application filed August 20, 1930. Serial No. 476,683.

This invention is a novel improvement in rotary hammer drills andthe'prlncipal object of the hammer drill particularly adapted for o landwater well drilling and for mineral and m ne tests and the like, mynovel drill being adapted to take the place of the rotary drllls now inuse and being adapted to drill a core readily and efliciently throughany stratum or rock which it may encounter in such drilling operation.

A furtherobject of the invention is to r o= vide a combined hammer androtary 13111 in which the hammer is positively rotated and in turnrotates by friction the drill bit by reason of complementary ratchetteeth on the hammer and bit, the teeth of the hammer sliding over theteeth of the bit when the rotatable bit is held stationary or rotationsufliciently retarded by engagement 0 to enable others familiar with theart to adopt and use the same; and will summarize in P the claims thenovel features of COIlStIIlClZlOIl,

and novel combinations of parts, for which protection is desired.

In said drawings Fig. 1 is a longitudinal section through one form of mynovel rotary hammer drill showing the hammer in normal position.

Fig. 2 is a similar longitudinal section through a modified form.

Fig. 3 is a sectional view showing the hammer in raised position and theratchet teeth of the hammer on the point of sliding over the upper endsof the teeth on the bit, to

invention is to provide a rotary' hereinafter described. Around thereduced permit a blow by the hammer on the cutting head of the bit.

Fig. 4 is a section on the line 44 Fig. 3.

As shown my invention comprises a block 1 of suitable weight, shape andproportions slightly reduced in diameter at each end forming a centralannular shoulder, the reduced portions being externally threaded. Block1 is provided with a central bore 1a extending entirely through theblock which bore is tapped at its upper end to receive the threadedlower end. of a pipe 3. Threaded onto the lower end of block 1 is adrill bit 2 of an desired type having an internally threa edannular'fiange 20 on its upper end adapted to engage the threadedlowerend of block 1. Bit 2 is also provided with .an axial bore 2?)which registers with bore 1a of block 1. Threaded onto the upperf end ofblock 1 is a cylindrical casing 4 housing the pipe '3,'the block 1, bit2, pipe 3, and easing 4 rotating as a unit. Upon the upper end of block1 within the casing 4 are raised annularly arranged ratchet teeth 16,

one face of each of the teeth 16 being out ver- 5 tically or parallelwith the axis of pipe 3.

Above block 1 within casing 4 is a slidable rotating hammer 5, having anaxial bore 5a loosely receiving pipe 3, and having a reduced lower end56 of diameter slightly less than the internal diameter of the annularteeth 16 on block 1,' said reduced end 56 being adapted to fit withinteeth lb'and strike a blow upon the upper end of the block 1 as ortion5b,of hammer 5 are annular disposed ratchet, teeth 50 corresponding withand complementary tothe ratchet teeth 16 on block 1, the said teeth 50and 1?) being normally in engagement, but when hammer 5 is rotatedin'the direction of the arrowFigs. 1, 2, 3 with respect to. block 1 thecam action of the ratchet teeth 50 sliding over teeth 1b will lifthammer 5 away from block 1 until teeth 50 run over' the the tops oftheir related teeth 16 at which time hammer 5 will drop down again tostrike a blow upon block 1 due to the action of springs 9 and theperpendicularity of one face of each of said teeth. Preferably the tipsof teeth 50 lie slightly above the end of reduced portion 5?) so thatthe hammer impact will be delivered by portion 5?) uponthe center ofblock 1 within the ratchet teeth 1?) instead of being delivered by teeth50 upon teeth 15.

The upper end of hammer 5 is slightly reduced in diameter as at 5d toreceive the open end of a cylindrical cap 6 which cap is adapted totelescope the hammer 5. The closed upper end 6a of cap 6 is providedwith a tapped central bore which receives the lower threaded end of themain or upper rotating pipe 7 whereby as pipe 7 is rotated the cap 6will likewise be rotated. The lower pipe 3 extends upwardly from block 1through hammer 5, through cap 6, and enters into the lower end of pipe7, pipe 8 being slightly smaller in diameter than pipe 7. Rotation ofpipe 7' does not necessarily rotate pipe 8 and block 1, the block 1being rotated as hereinafter described. The cap 6 is provided adjacentits lower open end with two sets of diametrically opposed longitudinalslots 6?) adapted to engage four studs 50 tapped into theside of hammer5 adjacent its upper end whereby hammer 5 1S permitted to telescope thecap 6 a distance sufficient to permit its ratchet teeth 50 to overridethe ratchet teeth 12') of block 1, while causing hammer 5 to bepositively rotated by and with pipe 7 by means of cap 6. Hence pipe 7,cap 6, and hammer 5 always rotate together as a unit. The heads of studspreferably lie substantially flush with the outer periphery of cap 6 soas to form a smooth outer surface for cap 6 which rotates within thecylindrical casing 4.

Threaded into the upper end of the cylindrical casing i is a hen ringblock 8 provided with a central bore 80 for the passage therethrough ofpipe 7, the ends of the bore 8a being countersunk to form taperedbearing seats 87) into the upper one of which enters an annular taperedshoulder 7a formed upon the pipe 7. shoulder seating in the top bearingseat 81) and carrying the entire weight of pipe 7. A similar annulartapered shoulder 60 is provided on the head 6a of cap 6 surrounding pipe7, which shoulder 60 engages the lower tapered bearing seat 8?) in thebearing block 8.

As shown in Figs. 1 and 3 within cap 6 and around pipe 3 between thehead 601 and hammer 5 is a coiled spring 9. If desired a buffer plate 6dmay be inserted between spring 9 and hammer 5. As the hammer 5 is movedupwardly in the casing 2 as hereinafter described spring 9 will becompressed as in Fig. 3 storing up energy to drive the hammer 5downwardly when the ratchet teeth 50 of hammer 5 slide over the tops ofthe teeth 1?) of block 1.

In Fig. 2 a modification is shown in which spring 9 is replaced by acompressible casing 9a, said casing being annular in shape and fittingaround pipe 3 and having a valve stem 95 passing through the head 6a ofcap 6 which stem may be provided with the usual Valve 90,

whereby the casing may be charged with air or other compressible fluid.The compressible fluid casing 9a operates in substantially the samemanner as the spring 9.

The upper end of easing 4 is closed by a.

head 10 having a bore 10a and a stuffing box 11 surrounding pipe 7. Inassembling the rotary hammer drill, bit 2 is threaded onto the lower endof block 1, and pipe 3 threaded into the upper end of block 1; casing 4is then threaded onto the upper end of block 1 over the ratchet teeth1?). Spring 9 or the compressible casing 9a is then placed into the cap6 with the valve 9a extending through the head 6a and hammer 5 insertedinto cap 6. The holes for the studs 50 of the hammer should then bealigned with the enlarged holes at the lower end of slots 6?) of cap 6,and screws 5e inserted and screwed down until the head of the screws liewithin the walls of cap 6 and the bolt heads are in line with the slots6?). The air sack 9a should then be pumped to whatever pressure neededto strike the proper blow, governed by the hardness of the rock. Thenassemble the bearing block 8 by placing the bearings into the block andinsert block 8 against the bearing 60 of the head 6a of cap 6 and extenddrive pipe 7 through the bearing block 8 and screw the pipe into cap 6until the shoulder 7a on pipe 7 rests against the upper bearing seat87). Place members 5. 6, 7 and 8 into casing 4 and screw bearing block 8to the bottom of the threads in casing 4; then slip head 10 over pipe 7and screw into casing 4. Pack stuffing box 11 on head 10 and screw intoplace around pipe 7. The machine is now ready for drilling.

The machine is then lowered into the bottom of the well and operates asfollows; the cutting edges of the drill bit 2 take hold of thebottom ofthe well and hold the bit 2, and block 1 with its ratchet in an initialstationary position. The drive pipe 7 is then revolved in the directionof the arrow Fig. 1 and cap 6 and hammer 5 are accordingly rotated. Theratchet teeth 50 on hammer 5 tend to climb over the ratchet teeth 1?) onblock 1 which raises hammer 5 upwardly and compresses the air easing 9aor spring 9. As teeth 50 slide over teeth 15 the hammer 5 is forciblydriven down against the head of block 1, transferring the blow to thedrill bit 2. causing the cutting edges to penetrate the bottom of well.The friction of the ratchet teeth 5b which is exerted on the ratchetteeth 1?) of block 1 causes the entire assembly to rotate as it cutsuntil bit 2 15 restrained from rotation due to its engagement with theground: and immediately the"hammer is raised and a blow impacted uponthe block 1 of the bit which should dislodge the bit or free same fromits restraining element.

The usual water circulation passes through pipes 7 and 3 at the centerof the assembly and passes out through the holes 26 in the bottom ofdrill bit 2 removing the cuttings. I do not limitmy invention to theexact forms shown in the drawings for obviously.

'overrunning of the hammer teeth upon restrained rotation of the drillbit to raise the hammer and compress the compressible member therebyaugmenting the weight of the hammer on its down stroke when the teethre-engage. v

2. 'In a drill as set forth in claim 1; said ratchet teeth beingannularly arranged, and a reduced end on the hammer disposed centrallyof its teeth adapted to engage the bit centrally of its teeth when theteeth are ena ed. g In a drill as set forth in claim 1, saidcompressible member comprising a coiled spring above the end of thehammer within the cap.

4. In a drill as set forth in claim 1, said compressible membercomprising a compresbore; a hammer member slidably and rotatably mountedon said pipe above the bit; a

4 cap around the upper end of said-hammer having a splined engagementtherewith;

, means for preventing separation of the drill bit and cap; a'rotarydrive pipe for rotating the cap, the fixed pipe loosely entering thelower end of the drive pipe; a compressible member within the cap;and-normally engaging ratchet teeth on the bit and hammer for rotatingby friction the bit with the hammer, and for permitting overrunning ofthe hammer teeth upon restrained rotation of the drill bit to raise thehammer and compress the compressible member, thereby augmenting theweight of the hammer on its down stroke when the teeth re-engage.

6. In a drill as set forth in claim 5; said ratchet teeth beingannularly arranged, and I a reduced end on the hammer disposed centrallyof its teeth adapted to engage the bit .centrally of its teeth when theteeth are engaged.

7. In a drill as set forth in claim 5; said compressible membercomprising a coiled spring above "the end of the hammer within the ca 8.n a drill as set forth in claim 5, said compressible member comprising acompressible fluid chamber abovethe end of the hammer within the cap; astem on the chamber extending through cap; and a valve in said stem.

9. A rotary hammer drill comprising a drill bit; a cylindrical casingsecured to the upper end of said bit; a cylindrical hammer slidably androtatably mounted within the casing; a cap around the upper end of saidhammer having a splined engagement therewith; a bearing in the upper.end of the easing for preventingseparation of the drill bit and cap;means for rotating the cap; a compressible member within the cap; andnormally engaging ratchet teeth on the bit and hammer for rotating byfrictlon the bit with the hammer, and for permitting overrunning of thehammer teeth upon restrained rotation of the drill bit to raise thehammer and compress the compressible member, thereby augmenting theweight of the hammer on its down stroke when the teeth re-engage.

10. In a drill as set forth in claim 9; said ratchet teeth beingannularly arranged, and a reduced end on the hammer disposed centrallyof its teeth adapted to engage the bit centrally of its teeth when theteeth are enga e 11. In a drill as set forth in claim 9, saidcompressible member comprising a coiled spring above the end of thehammer within the cap.

12. In a drill as set forth in claim 9, said compressible membercomprising a compressible fluid chamber above the end of the hammerwithin the cap; a stem on the chamber extending through cap; and a valvein said stem.

13. A rotary hammer drill comprising a drill bit; a cylindrical casingsecured to the upper end of said bit; a cylindrical hammer slidably androtatably mounted within the casing; a cap around the upper end of saidhammer having a splined engagement therewith; a bearing in the upper endof the easing for maintaining the cap and drill bit in fixed relation; adriving member extending down through the bearing for rotating the cap;a tapered shoulder on said driving mem ber engaging a tapered bearingseat in the block for supporting the driving member; a compressiblemember within the cap; and normally engaging ratchet teeth on the blockand hammer for rotating by friction the bit with the hammer, and forpermitting overrunning of the hammer teeth upon restrained rotation ofthe drill bit to raise the hammer and compress the compressible member,thereby augmenting the weight of the hammer on its down stroke when theteeth reengage.

. 14. In a drill as set forth in claim 13, said ratchet teeth beingannularly arranged, and a reduced end on the hammer disposed centrallyof its teeth adapted to engage the bit centrally of its teeth when theteeth are engaged. v

15. In a drill as set forth in claim 13, said compressible membercomprising a coiled spring above the end of the hammer within the cap.

16. In a drill as set forth in claim 13, said compressible membercomprising a compressible fluid chamber above the end of the hammerwithin the cap; a stem on the chamber extending through cap; and a valvein said stem.

17. A rotary hammer drill, comprising a drill bit having a bore; acylindrical casing secured to the upper end of said bit; a pipeextending upwardly through the casing and fixed in the bore; acylindrical hammer around the pipe and slidably and rotatably mountedwithin the casing; a cap around said pipe and around the upper end ofsaid ham mer having a splined engagement with the hammer; a bearing inthe upper end of said casing; said cap engaging the lower end of theblock to prevent separation of the cap and drill bit; a drive pipe forrotating the cap; said drive pipe extending down through the bearing; atapered shoulder on said pipe engaging a tapered bearing seat in thebear ing for supporting the weight of the drive pipe; the upper end ofthe fixed pipe entering the lower end of the drive pipe; a compressiblemember within the cap; and normally engaging ratchet teeth on the bitand hammer for rotating by friction the bit with the hammer, and forpermitting overrunning of the hammer teeth upon restrained rotation ofthe drill bit to raise the hammer and compress the compressible member,thereby augmenting the weight of the hammer on its down stroke when theteeth re-engage.

18. In a drill as set forth in claim 17; said ratchet teeth beingannularly arranged, and a reduced end on the hammer disposed centrallyof its teeth adapted to engage the bit centrally of its teeth when theteeth are engaged.

19. In a drill as set forth in claim 17, said compressible membercomprising a coiled spring above the end of the hammer within the cap.

20. In a drill as set forth in claim 17, said compressible membercomprising a compressible fluid chamber above the end of the hammerwithin the cap; a stem on the chamber extending through cap; and a valvein said stem.

GUSTAVIS ADOLPHIS BXLLSTROM.

